The binary

Either tranvestism and transsexualism (forgive the older terms) are on the same lineage or they are not and I think it is the former which is true with the main differentiator being the presence and strength of gender dysphoria. Something which almost certainly has genetic roots.

It can generally be said that one individual tends to seriously weigh transition while the other does not but in the middle point is where it becomes nebulous. In essence I am once again agreeing with Harry Benjamin because I have no good reason not to, even as that model may have inherent imperfections.

I know too many transfeminine people over the years who can comfortably be placed somewhere on this lineage which I also think applies well to natal females who were identified later due to their greater ability to hide in plain sight.

People in general are also not really as binary as it would appear and never were, hence today's greater experimentation with loosening restrictions. What we are is more fluid but we subjugated to societal norms to avoid being ostracized. 

However I continue making the distinction between variance by choice and that of by necessity (without prejudice) because it is an important one. Again, it's the "what I do" versus "who I am".